请快一点,求各位数学大王了!急~~~答:132,134,140,142,143,201,203,204,210,213,214,230,231,234,240,241,243,301,302,304,310,312,314,320,321,324,340,341,342 ,401,402,403,410,412,413,420,421,423,430,431,432,4 ,我的钟霉天慢十分钟,多少天后分针将指到一个正确的位置?只是分针的话那就是6天后.刚好一圈 ...
有1,2,3,4个数字,能组成多少个互不相同且无重复数字的三位数?都是多少...答:24个。123,132,213,231,312,321;124,142,214,241,412,421;134,143,314,341,413,431;234,243,324,342,423,432。